Latent common genetic components of obesity traits.
BACKGROUND
Obesity is rapidly becoming a global epidemic. Unlike many complex human diseases, obesity is defined not just by a single trait or phenotype, but jointly by measures of anthropometry and metabolic status.


METHODS
We applied maximum likelihood factor analysis to identify common latent factors underlying observed covariance in multiple obesity-related measures. Both the genetic components and the mode of inheritance of the common factors were evaluated. A total of 1775 participants from 590 families for whom measures on obesity-related traits were available were included in this study.


RESULTS
The average age of participants was 37 years, 39% of the participants were obese (body mass index >or= 30.0 kg/m(2)) and 26% were overweight (body mass index 25.0-29.9 kg/m(2)). Two latent common factors jointly accounting for over 99% of the correlations among obesity-related traits were identified. Complex segregation analysis of the age- and sex-adjusted latent factors provide evidence for a Mendelian mode of inheritance of major genetic effect with heritability estimates of 40.4 and 47.5% for the first and second factors, respectively.


CONCLUSIONS
These findings provide a support for multivariate-based approach for investigating pleiotropic effects on obesity-related traits, which can be applied in both genetic linkage and association mapping.
Tayo
B O
BO
Department of Preventive Medicine and Epidemiology, Loyola University Chicago, Stritch School of Medicine, Maywood, IL 60153, USA. btayo@lumc.edu
Harders
R
R
Luke
A
A
Zhu
X
X
Cooper
R S
RS
D000328:Adult; D001741:Black or African American / Q000235:genetics*; D001823:Body Composition / Q000235:genetics; D015992:Body Mass Index; D049628:Body Size / Q000235:genetics; D001835:Body Weight / Q000235:genetics; D002641:Chicago; D005190:Family; D005260:Female; D008040:Genetic Linkage; D020022:Genetic Predisposition to Disease / Q000235:genetics*; D006801:Humans; D016013:Likelihood Functions; D008297:Male; D008875:Middle Aged; D008957:Models, Genetic; D009765:Obesity / Q000235:genetics*; D018570:Risk Assessment; D055815:Young Adult